BMW S1000RR Forum banner
101 - 120 of 200 Posts
Thanks for your input Andy, I knew it was just a matter of time before someone with some actual knowledge would show up! Almost all of my experience is on 2012s or earlier, they seem VERY tolerant to size changes, the only limit being unable to get the tire warmers on.
 
Discussion starter · #102 · (Edited)
I want to thank AndyHP4 for taking time to explain all of this to me in several pm's.

So after picking his brain and having him basically go step by step with this I feel very comfortable now trying just about any tire size.

Now this is my understanding - if I'm still wrong I'm sure Andy will jump in.

The DTC is calibrated from BMW for the tire size the bike was shipped with.

Sure there is a certain percentage of margin for tire sizes between different brands - might be 10%.

The DTC will change if the tire size gets out of the permissible range. If the tire is smaller either say going from a 200 to a 190 for instance and the actual size is say more than 10% of the original calculation BMW used then the DTC would kick in sooner. If going from a 190 to a 200 then it would kick in later - keep in mind this is if you are keeping the same aspect ratio for instance a 55.

Now when you change the aspect ratio say from a 55 to 60 and that in fact again is say more than 10% of the original calculation BMW used it will most certainly change how soon the DTC kicks in - in the case of going bigger/taller the DTC kicks in later.

And of course when you go from say a 190/55/17 to a 200/60/17 - again if that new tire is bigger/taller/wider than the factory settings for DTC by say 10% again the DTC will kick in latter - if going from a 200/55/17 to a 190/60/17 for example - same deal you will have to see how much the tire size is different from the factory based settings.

All of this applies to the front tire size as well. Remember I have a 2015 with DDC as well.

In my case I want to go from Pirelli Supercorsa SC2's front 120/70/17 and rear 200/55/17 to Pirelli Race slicks same front size but a 200/60/17 rear.

So in my case the DTC is going to kick in most likely much later than what it does now.

So going into slick mode - we can adjust the DTC manually - from the factory it is set at 0. You can adjust it up or down from +7 to -7.

The + numbers equals the sooner the DTC kicks in so +7 it kicks in the earliest and -7 the latest.

So to be on the safe side first time out on these slicks I might set the DTC to +7 and see how the DTC acts. If it kicks in too soon I will go to a lower setting until I find what I'm comfortable with.
 
Good summary!

On the track what mode/settings do you usually run?

Does the DTC flash for you on corner exists? My last track day I had the bike in race mode and on few turns with the throttle pinned on corner exists DTC light would flash. Do I need to reduce DTC (-1 or -2) in race mode so it kicks in later?
 
Discussion starter · #104 ·
Good summary!

On the track what mode/settings do you usually run?

Does the DTC flash for you on corner exists? My last track day I had the bike in race mode and on few turns with the throttle pinned on corner exists DTC light would flash. Do I need to reduce DTC (-1 or -2) in race mode so it kicks in later?
Zoo:

All last year I ran in Race Mode - I honestly never felt/saw the DTC flash - not once. I checked it in Rain and Sport Modes and it in fact worked. I could even get it to kick in on the straight a few times.

Well do you want it to intervene less is the question - maybe having it kick in for those few occasions is not a bad thing.

Also unless I'm confused again - you can't adjust the DTC in Race Mode - only in Slick/User Modes
 
You're right, maybe having DTC kick in a bit is a good idea. I thought reducing DTC a bit would let a little wheelspin which would help the bike. But it's more risky than it's worth.

I'm the one who is confused. I thought settings (DTC, etc...) are overridable per mode and not only in user/slick mode.

When in race mode, if we hit DTC button -/+ would not that override it in race mode only?

I'm not sure if ABS, and other settings can be overridden in other modes beside user/slick. I ride in race or user mode. I have not tried the above.
 
Discussion starter · #106 ·
You're right, maybe having DTC kick in a bit is a good idea. I thought reducing DTC a bit would let a little wheelspin which would help the bike. But it's more risky than it's worth.

I'm the one who is confused. I thought settings (DTC, etc...) are overridable per mode and not only in user/slick mode.

When in race mode, if we hit DTC button -/+ would not that override it in race mode only?

I'm not sure if ABS, and other settings can be overridden in other modes beside user/slick. I ride in race or user mode. I have not tried the above.
Zoo:

The only modes that you can adjust DTC is in Slick/User Modes - you can turn the DTC off in any mode.
 
If you're in doubt, then run in RACE MODE or SPORT MODE. Remember also that the slicks with proper inflation and temperature will have much more grip than street tires.

I would work into the power/grip/intervention until you're comfortable. Slicks are going feel very different to you. These are general statements and advice, not bike specific.
 
My 2015 was shipped with 200/55. I changed to a 200/60 slick rear and the TC still seems to work exactly the same. It appears to activate no sooner or later in the corners as the 200/55. I'm not a racer but I'm in the fast group pushing the bike and tyres pretty hard. I have always had it in "Race" mode, I haven't yet felt the need to alter the traction control settings to let it spin/slide a bit more. I have slick $ user mode but all the settings I want are standard race mode.
 
My 2015 was shipped with 200/55. I changed to a 200/60 slick rear and the TC still seems to work exactly the same. It appears to activate no sooner or later in the corners as the 200/55. I'm not a racer but I'm in the fast group pushing the bike and tyres pretty hard. I have always had it in "Race" mode, I haven't yet felt the need to alter the traction control settings to let it spin/slide a bit more. I have slick $ user mode but all the settings I want are standard race mode.
The difference is less than 2mm in radius so you can't actually feel a 0.5% later intervention of the DTC - just measure both tyres circumferences and you will see what I mean.
 
With the Race calibration kit you can change tire radius. I did not had enough time to experiment with mine but putting a larger rear you get later activation of the DTC, as its been mentioned above.
Couple of years ago (before upgrading to Race ECU) went to Misano and used a 190/55 rear tire the 1st day and equivalent to 200/55 rear for 2 days. The 1st day the DTC intervened couple of times but the 2-3nd day none. Believe me I was pushing way harder the 2-3rd day (5sec improvement). Even in Variante del Parco I was opening the throttle and felt the rear spin a lot of times and yes there was no DTC.
Here is the telemetry of that particular turn.

Image


As you can see GPS speed is 132 and rear is 155. There is a difference of appx 20km in speed. BUT actually rear tire speed is more because this is a 200/55 tire. DTC is calibrated for 190/55 and it shows less speed than it really has for the rear tire. It permitted me to go a bit further in tire spin of the rear tire. Not by a lot but just right for the DTC not to kick in. The actual rear tire speed is something I cannot accurately measure since the tire was not a Pirelli or Metzeler (ECU calibrated) but a Dunlop.

Also 10% difference in tire radius is more than 30mm. It really is big difference. With the HP4 and >15 models you can adjust DTC intervention but if you are not within the ECU parameters your DTC is going to light whatever you do with DTC intervention.
 
Discussion starter · #114 ·
I got in touch with the local Pirelli Race tire dealer. I asked him if he had the actual tire measurements for the two tires I was interested in.

Last year I ran DOT Supercorsa SC2's - front 120/70/17 - rear 200/55/17.

I want to go with Pirelli Race Slicks - front 120/70/17 - rear 200/60/17.

He sent me these measurements:

Supercorsa 200/55
195mm wide
656mm diameter

Superbike 200/60
200mm wide
662mm diameter

Based on these measurements the DTC is going to intervene slightly later - my guess not even noticeable.
 
That's the max radius in the middle of the tyre if you are riding in a straight line, but
- DTC doesn't intervene at 0 degree lean
- DTC needs to know the change in radius every lean up to 60 degrees and here is a huge difference in the profile on a street legal 200/55 and a slick in 200/60

Just be aware that the DTC will probably intervene later than you expect so start with more DTC than normal.
 
So has anyone actually gone from a 200 rear to a 190? i know there is alot of info in this thread and after reading it, i didnt see anyone who had actually done it. im almost done with another set of tires, this time in about 3 months. Wanting to explore tire choices but 200 choices are pretty limited. I ran M7rrs last time.
 
So has anyone actually gone from a 200 rear to a 190? i know there is alot of info in this thread and after reading it, i didnt see anyone who had actually done it. im almost done with another set of tires, this time in about 3 months. Wanting to explore tire choices but 200 choices are pretty limited. I ran M7rrs last time.
I know of a guy that did, he had no issues.

I use 190 for the street (what my bike is setup for), and 200 for the track (slicks), and I don't have issues. However, due to the slight change in diameter of the tire, I compensate the DTC on slick mode by 1-2 steps. If I want minimal intervention, then I do -5, maybe -6, but never -7.

Going from a 200 to a 190, you'll have the opposite problem, so it's super safe to do.

You'll have absolutely no problems on the street and canyons. For the track, DTC may intervene a bit more than usual, so keep it 1-2 steps lower than usual.
 
101 - 120 of 200 Posts